US3787749A - Automatic synchronizing system - Google Patents

Automatic synchronizing system Download PDF

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Publication number
US3787749A
US3787749A US00851589A US3787749DA US3787749A US 3787749 A US3787749 A US 3787749A US 00851589 A US00851589 A US 00851589A US 3787749D A US3787749D A US 3787749DA US 3787749 A US3787749 A US 3787749A
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United States
Prior art keywords
synchronizing
circuit
synchronism
control circuit
sampling device
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Expired - Lifetime
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US00851589A
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English (en)
Inventor
K Uchida
N Nakaya
K Suzuki
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IWATA ELECTRIC CO
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IWATA ELECTRIC CO
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R13/00—Arrangements for displaying electric variables or waveforms
    • G01R13/20—Cathode-ray oscilloscopes
    • G01R13/22—Circuits therefor
    • G01R13/32—Circuits for displaying non-recurrent functions such as transients; Circuits for triggering; Circuits for synchronisation; Circuits for time-base expansion

Definitions

  • an automatic synchronizing system comprising a synchronizing circuit including a variable element, a sampling device and a synchronism control circuit which operates to differentiate the output from the sampling device to vary the variable element, to stop the variation of the variable element and to maintain the stopped condition
  • a control circuit responsive to the cessation of operation of either one of the synchronizing circuit or the sampling device to start either one of the synchronizing circuit, sampling device and the synchronism control circuit to continue to find a point of synchronism even in the absence of a synchronizing signal for a predetermined interval or even when the amplitude of the synchronizing signal is small.
  • a time axis circuit may be added which may be controlled by the control circuit in the same manner.
  • FIG. 2 g SYNCHRON I Z NG l5 CKT 2 SAMPLING SYNCHRONISM CKT CONT c FIG. 2
  • This invention relates to a novel automatic synchronizing system for apparatus requiring a synchronizing signal such as an oscilloscope, a pulse generator and the like or a sampling device such as a sampling oscilloscope, wherein an output pulse synchronized with a synchronizing signal input can be stably and automatically derived out and a point of synchronism can be automatically obtained by controlling a variable element in the synchronizing circuit even when the amplitude of the synchronizing signal input is small or there is no such signal input.
  • a synchronizing signal such as an oscilloscope, a pulse generator and the like or a sampling device such as a sampling oscilloscope
  • the frequency, amplitude and waveform of the synchronizing input signal vary in various manner, in order to provide output pulses synchronized with'such various input signals it has been the practice to manually vary the synchronizing level of the signal inputs in the synchronizing circuit or to set the synchronizing circuit in the self exciting condition to manually vary its frequency of self excitation.
  • a variable element such as voltage or current of the synchronizing circuit is varied by manually adjusting it.
  • an input terminal 110 for the synchronizing signal input is connected to a synchronizing circuit 111 and the output of circuit Ill and the synchronizing signal input or a signal synchronized therewith are supplied to a sampling circuit 13 via an input terminal 12 to provide a sampling signal of the input signal.
  • the sampling signal is treated in a synchronism control circuit 14 to vary a variable element (not shown) in the synchronizing circuit 11 by the output from the synchronism control circuit 14.
  • Synchronism control circuit 14 operates to differentiate the sampling signal to stop the variation of the variable element in the synchronizing circuit when the amplitude of the differentiated waveform becomes minimum whereby to automatically maintain this condition.
  • V(t) represents the waveform that is sampled by sampling circuit 13 and maintained thereby and that Y represents the differentiated value of V(t) with respect to time
  • Y will be shown by The absolute value of Y, that is lYl becomes minimum when a point of synchronism is reached.
  • 1 Y1 manifests its minimum value at a single point or a plurality of points.
  • FIG.2 shows a case wherein I Y] has a single minimum value, but following explanation applies equally irrespective of the number of minimum values of lYl.
  • the abscissa represents the variable element and the value of X corresponding to the minimum value of i Y] is represented by Xo.
  • the value of X will be very close to Xo.
  • X begins to vary again to search the point of lYlmin or a point very close thereto, and upon finding such point X is fixed to that point.
  • the synchronism control circuit 14 operates to automatically fix the value of X at or near lYlrnin.
  • the synchronizing circuit does not operate in the absence of any synchronizing signal input but operates upon reception of a synchronizing signal to generate a signal synchronous therewith, and that the synchronizing circuit performs self excitation, even in the absence of the synchronizing signal, to generate a pulse in a range from Xc to Xz then between Xa and X0, the sensitivity of the circuit to the synchronizing-signal input decreases toward Xa.
  • the synchronizing circuit senses-only large synchronizing signal inputs and increases its sensitivity from Xa to Xe.
  • the synchronizing circuit operates to convert a received synchronizing signal having a frequency higher than its frequency of self excitation into a pulse of a frequency lower than a definite frequency synchronous to said synchronizing frequency by the pull-in phenomenon.
  • Another object of this invention is to provide an im proved synchronizing system suitable for use in oscilloscopes, pulse generators, and sampling devices such as sampling oscilloscope which require a synchronizing signal.
  • an automatic synchronizing system comprising a synchronizing circuit including a variable element, a sampling device, a synchronism control circuit which operates to differentiate the output from the sampling device to vary the variable element, to stop variation of the variable element upon reaching synchronism and to maintain the stopped condition and a control circuit which senses stopping of operation of either one of the synchronizing circuit and the sampling device to start either one of the synchronizing circuit, sampling device and the synchronism control circuit to continue to find out a point of synchronism even in the absence of a synchronizing signal for a predetermined interval or even when the amplitude of the synchronizing signal is small.
  • a time axis circuit is added to the automatic synchronizing circuit which is similarly controlled by the control circuit.
  • FlG.l is a block diagram of an automatic synchronizing system, as disclosed in applicants copending application.
  • FIG.2' show a graph to explain the principle of the automatic synchronizing system
  • FIGS. 3 and 4 are block diagrams illustrating different embodiments of this invention and FIG.5 shows a block diagram of a sampling device of a sampling oscilloscope and the like.
  • FIG.3 illustrating a block diagram of this invention a control circuit 16 for controlling-synchronizing circuit 11 is added to the block diagram shown in FIGJ.
  • the control circuit functions to initiate its operation when the synchronizing circuit 11 stops its operation for more than a predetermined interval to provide an output pulse for the synchronizing circuit.
  • control circuit 16 operates to'cause synchronizing circuit 11 to generatean output pulse of lOKHz every 100 microseconds even when the amplitude of the synchronizing signal applied to the synchronizing circuit is small or even when there is no synchronizing signal.
  • a sampler 13 causes the synchronism control circuit 14 to operate to constantly find the point of synchronism.
  • control circuit 11 in response to the cessation of operation of the synchronizing circuit for more than a predetermined interval, operates to start synchronism control circuit 14 to cause it to find out the point of synchronism even in the absence of the synchronizing signal or even when the amplitude thereof is small.
  • control circuit such that it will sense cessation of the operation of sampler 13 for more than a predetermined interval so as to start synchronizing circuit 16 or synchronism control circuit 14.
  • control circuit 16 senses cessation of operation of the synchronizing circuit 11 to start the same, the control circuit 16 may be arranged to start sampler 13 or synchronism control circuit 14. In the same manner, the control circuit 11 shown in FIG.4 can also be-arranged to start sampler 13 or synchronism control circuit 14. Further, while in said two embodiments control circuit 16 is constructed to sense stopping of operation of the synchronizing circuit, according to this invention, control circuit 16 can also be arranged to sense cessation of the operation of either one of sampler 13 and synchronizing circuit 11 to start either one of synchronizing circuit ll, sampler l3 and synchronism control circuit.14.
  • this invention is also applicable to a sampling device such as a sampling oscilloscope and the like.
  • a sampling device such as a sampling oscilloscope and the like.
  • the block diagram of such a sampling device includes a time axis circuit 16 interposed between the synchronizing circuit 11 and terminal 15 of FIG.1 and, as a result, it is seen that the invention is applicable to such a circuit.
  • the control circuit provided in accordance with this invention is arranged to sense cessation of operation of at least one of synchronizing circuit 11, sampler circuit 13 and item axis circuit 16' to start either one of synchronizing circuit 11, sampling circuit 13, time axis circuit 16' and synchronism control circuit 14.
  • a control circuit for effecting the control function described above is provided thus enabling the point of synchronism even in the absence of the synchronizing signal over a predetermined interval or when the amplitude thereof is small.
  • the synchronizing system of this invention can be used with advantages for devices which require synchronizing signals such as an oscilloscope and a pulse generator as well as for sampling devices and the like.
  • an automatic synchronizing system having a synchronizing circuit including a variable element, a sampling device, and a synchronism control circuit which operates to differentiate the output from said sampling device to vary said variable element in said synchronizing circuit, said synchronism control circuit further operating in response to a minimum in said differentiated output to stop said variation of said variable element upon reaching synchronism and to maintain the stopped condition, the improvement which comprises control circuit means for sensing stopping of operation of either one of said synchronizing circuit and said sampling device and operablein response to said stopping to start at least one of said synchronizing circuit, sampling device or said synchronism control circuit to continue to find a point of synchronism even in the absence of a synchronizing signal for a predetermined interval or even when the amplitude thereof is small.
  • a sampling device such as a sampling oscilloscope having a synchronizing circuit including a variable element, a sampling device, a time axis circuit and a synchronism control circuit which functions to differentiate the output from said sampling device to vary said variable element in said synchronizing circuit
  • said synchronizing control circuit also functioning in response to a minimum in said differentiated output to stop said variation of said variable element upon reach- 6 sampling device, synchronism control circuit or time axis circuit to continue to find a point of synchronism even in the absence of a synchronizing signal for a predetermined interval or even when the amplitude thereof is small.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
US00851589A 1968-08-23 1969-08-20 Automatic synchronizing system Expired - Lifetime US3787749A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP43059921A JPS4941706B1 (de) 1968-08-23 1968-08-23

Publications (1)

Publication Number Publication Date
US3787749A true US3787749A (en) 1974-01-22

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Application Number Title Priority Date Filing Date
US00851589A Expired - Lifetime US3787749A (en) 1968-08-23 1969-08-20 Automatic synchronizing system

Country Status (5)

Country Link
US (1) US3787749A (de)
JP (1) JPS4941706B1 (de)
DE (1) DE1942887C3 (de)
GB (1) GB1287152A (de)
NL (1) NL6912822A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4475085A (en) * 1980-09-25 1984-10-02 Tokyo Shibaura Denki Kabushiki Kaisha Clock synchronization signal generating circuit
US4560939A (en) * 1984-04-02 1985-12-24 Sperry Corporation Synchronized selectable rate clocking system
US10122100B1 (en) * 2018-03-16 2018-11-06 Lee Reeves Terminal block assemblies

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2863055A (en) * 1956-07-11 1958-12-02 Hycon Mfg Company Sweep generator
US2980858A (en) * 1959-12-07 1961-04-18 Collins Radio Co Digital synchronization circuit operating by inserting extra pulses into or delayingpulses from clock pulse train
US3080487A (en) * 1959-07-06 1963-03-05 Thompson Ramo Wooldridge Inc Timing signal generator
US3153762A (en) * 1962-06-12 1964-10-20 Johnson Alan Barry Pulse insertion circuit for detecting missing pulses and for inserting locally generated, synchronized pulses therefor
US3213375A (en) * 1963-08-01 1965-10-19 Arnoux Corp Synchronized controlled period pulse generator for producing pulses in place of missing input pulses

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2863055A (en) * 1956-07-11 1958-12-02 Hycon Mfg Company Sweep generator
US3080487A (en) * 1959-07-06 1963-03-05 Thompson Ramo Wooldridge Inc Timing signal generator
US2980858A (en) * 1959-12-07 1961-04-18 Collins Radio Co Digital synchronization circuit operating by inserting extra pulses into or delayingpulses from clock pulse train
US3153762A (en) * 1962-06-12 1964-10-20 Johnson Alan Barry Pulse insertion circuit for detecting missing pulses and for inserting locally generated, synchronized pulses therefor
US3213375A (en) * 1963-08-01 1965-10-19 Arnoux Corp Synchronized controlled period pulse generator for producing pulses in place of missing input pulses

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Instruction Manual for Tektronix Model 453 Oscilloscope, 1965. *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4475085A (en) * 1980-09-25 1984-10-02 Tokyo Shibaura Denki Kabushiki Kaisha Clock synchronization signal generating circuit
US4560939A (en) * 1984-04-02 1985-12-24 Sperry Corporation Synchronized selectable rate clocking system
US10122100B1 (en) * 2018-03-16 2018-11-06 Lee Reeves Terminal block assemblies

Also Published As

Publication number Publication date
DE1942887A1 (de) 1970-02-26
GB1287152A (en) 1972-08-31
NL6912822A (de) 1970-02-25
JPS4941706B1 (de) 1974-11-11
DE1942887C3 (de) 1973-12-20
DE1942887B2 (de) 1973-05-24

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